My research interests are primarily in energy conversion. Under the direction of Ajay Prasad and Suresh Advani at the University of Delaware, my previous research was focused around mass transport in Polymer Electrolyte Membrane (PEM) fuel cells. More recently, I am working with Arun Majumdar and Rachel Segalman to improve the effiency of thermoelectric energy generation and refrigeration.

Introduction to Thermoelectrics

If a temperatrure change is applied across a metal or semiconductor, there is an accompanying voltage response which can be used to do useful work. For metals, that voltage is extremely small; for example, aluminum produces a voltage response (Seebeck coefficient) of only 3 uV/K. However, many semiconductors have much higher Seebeck coefficient; Bi2Te3 for example can be made to have a Seebeck coefficient of 200 uV/K while maintaining high electrical conductivity (~300 S/cm). This makes thermoelectric materials a promising alternative for waste heat power generation and small scale refrigeration.

Efficiency and the Thermoelectric Figure-orf-Merit (ZT)

Thermoelectric materials are heat engines, and as such, have a finite efficiency which can never exceed the Carnot limit. In fact, it can be shown that the efficiency of a thermoelectric power generation system is related to only three material properties: S (the Seebeck coefficient), s (electrical conductivity), and k (thermal conductivity). In particular, the combination:

ZT=S*s*T/k

called the Thermoelectric Figure-of-Merit. Determines the effiency.

(UNDER CONSTRUCTION)